/**************************************************************************
***    
*** Copyright (c) 1995-2000 Regents of the University of California,
***               Andrew E. Caldwell, Andrew B. Kahng and Igor L. Markov
*** Copyright (c) 2000-2002 Regents of the University of Michigan,
***               Saurabh N. Adya and Igor L. Markov
***
***  Contact author(s): abk@cs.ucsd.edu, imarkov@umich.edu
***  Original Affiliation:   UCLA, Computer Science Department,
***                          Los Angeles, CA 90095-1596 USA
***
***  Permission is hereby granted, free of charge, to any person obtaining 
***  a copy of this software and associated documentation files (the
***  "Software"), to deal in the Software without restriction, including
***  without limitation 
***  the rights to use, copy, modify, merge, publish, distribute, sublicense, 
***  and/or sell copies of the Software, and to permit persons to whom the 
***  Software is furnished to do so, subject to the following conditions:
***
***  The above copyright notice and this permission notice shall be included
***  in all copies or substantial portions of the Software.
***
*** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
*** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
*** OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
*** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
*** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
*** OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
*** THE USE OR OTHER DEALINGS IN THE SOFTWARE.
***
***
***************************************************************************/




//created by Andrew Caldwell and Igor Markov on 09/19/98

#ifndef _GAIN_LIST__H__
#define _GAIN_LIST__H__

#include <vector>
using std::vector;
#include "ABKCommon/abkcommon.h"
#include "svGainElmt.h"

class GainList : public SVGainElement
{
  public:
    GainList() : SVGainElement() {}
    ~GainList() {}

    bool isEmpty() const { return _next == NULL; }

    SVGainElement& getFirst() const 
    { 	abkassert(_next != NULL, "can't call getFirst on an empty GList");
	return *_next;
    }

    void  pop();	//remove the item at the head
    void  push(SVGainElement& elmt); //add item at the head

    SVGainElement* getLastItem();

    void  insertAhead (GainList&);
    void  insertBehind(GainList&);

    bool  isConsistent();

    friend ostream& operator<<(ostream& os, const GainList&);
};


//____________________IMPLEMENTATIONS__________________________//

//_______GainList functions_____________//

inline void GainList::pop()
{	//the GList never owned the Element memory, so it does
	//not have to delete any of it.
    abkwarn(_next != NULL, "calling pop on an empty GB list");
    if(_next != NULL)
    {
	SVGainElement* toRemove = _next;
	_next = toRemove->_next;	//change the next ptr.
	toRemove->_next = NULL;		//disconnect the removed item
	toRemove->_prev = NULL;

	if(_next != NULL)
	    _next->_prev = this;
    }
}

inline void GainList::push(SVGainElement& elmt)
{
    elmt._prev = this;
    elmt._next = _next;
    if(_next != NULL)
	_next->_prev = &elmt;
    _next = &elmt;
}

inline SVGainElement* GainList::getLastItem()
{
    SVGainElement* last = _next;
    if(last == NULL)
	return NULL;
    for( ; last->_next != NULL; last = last->_next)
    {}

    return last;
}

inline void GainList::insertAhead (GainList& toAdd)
{
    if(toAdd._next == NULL)
        return;
    else if(_next == NULL)
    {
        _next = toAdd._next;
        _next->_prev = this;
    }
    else
    {
        SVGainElement* tmpTop = _next;
        _next = toAdd._next;
        _next->_prev = this;
        SVGainElement* toAddEnd = toAdd.getLastItem();
        tmpTop->_prev = toAddEnd;
        toAddEnd->_next = tmpTop;
    }
 
    toAdd._next = NULL;
}
 
inline void GainList:: insertBehind(GainList& toAdd)
{
    if(toAdd._next == NULL)
        return;
    else if(_next == NULL)
    {
        _next = toAdd._next;
        _next->_prev = this;
    }
    else
    {
        SVGainElement* mainListEnd = getLastItem();
        mainListEnd->_next = toAdd._next;
	mainListEnd->_next->_prev = mainListEnd;
    }
    toAdd._next = NULL;
}

inline bool GainList::isConsistent()
{
    SVGainElement *next, *prev;
    prev = this;
    next = _next;
    bool consistent = true;
    for( ; next != NULL; prev = next, next = next->_next)
    {
	if(prev->_next != next || next->_prev != prev)
	{
	    cout<<"gain list mismatch"<<endl;
	    consistent = false;
	}
    }
    return consistent;
}

inline ostream& operator<<(ostream& os, const GainList& lst)
{
    SVGainElement* cur = lst._next;
    if(cur == NULL)
	os<<" EMPTY "<<endl;
    else
    {
        for( ; cur != NULL; cur = cur->_next)
            os<<*cur<<" ";
        os<<endl;
    }
    return os;
}


#endif

